Spring-jack



- (No Model.) I

W. S. PACA.

I SPRING JACK.

No. 576,375. 7 Patented Feb. 2., 1897 Ullllllll! WITNESSIZS, I@ENVENTOR. I m H zZLLwmLYPacw. v m s ggy-1 UNITED STATES PATENT OFFICE.

IVILLIAM .S. PACA, OF BALTIMORE, MARYLAND.

SPRING-JACK.

SPECIFICATION forming part of Letters Patent No. 576,375, dated February2, 1897. Application filed September 23, 1896. $erial No. 606,758. (Nomodel.)

To ctZZ whom it nary concern.-

Be it known that LVVILLIAM S. PAOA, a citizen of the United States,residing in the city of Baltimore and State of Maryland, have invented anew and useful Improvement in Spring-Jacks and I do hereby declare thefollowing to be a full, clear, and exact descrip' tion of the same,reference being had to the accompanying drawings, in which- Figure Irepresents a notch-plug adapted to be used with this spring-jack. Fig.II is a transverse sectional View at the line as of Fig. I. Fig. 111 isa front View of a portion of a switchboard with the socket of one of myspring-jacks, and Fig. IV represents a portion of the switchboard andspring-jack in section with the switch-plug in side elevation.

This invention relates to that class of devices by means of whichdifferent lines of telegraphs or telephone-circuits maybe temporarilyconnected, its use being principally confined to central-exchangestations.

The object of this invention is to insure perfect contact and electricalcommunication between the metallic portions of the switchplug and theswitch-terminals of the springjack when the switch is closed and yetpermit so loose a fit of the switch-plug into the switch-sockets in thetable that the plug may be easily inserted or removed by the operator.

To this endmy invention consists in the construction and combination ofparts forming a springq'ack, hereinafter more fully described andclaimed.

Referring to the accompanying drawings, 5 represents a switch-plug; 7,the weight-cord therefor; 8 and 9, insulating-sections, and 10 and 11metallic sections of the plug with which wires concealed Within the cordhave connection, respectively.

12 and 13 represent lugs projecting from the sides of the metallicportion 10 and integral or having permanent metallic connectiontherewith.

14 represents a portion of a switchboard, which board usually contains alarge number of sockets, one of which is shown at 15 for the insertionof any one of a number of switchplugs 5. Each socket is provided with ametallic bushing 16, having longitudinal slots 17 at its sides toregister with and freely receive the lugs 12 13 when the plug isinserted into the socket. At the inner ends of these slots thepassage-ways for the lugs are offset'sidewise, forming recesses whichextend partly or wholly around within the bushing] 6, forming what istermed a bayonet-joint.

18 represents a metallic spring located in the bottom of the socket 15and provided with a button or piston 19 of metal to engage the metal end11 of the plug when the latter en.- ters the socket, and 20 represents awire which may be one of the members to be connected by switch-plug,while 21 represents a wire which may be another member to be connectedtherewith, the wire 21 being connected with the bushing 16 as aterminal.

It will be readily seen that if the sections 10 and 11 of the plug beconsidered as terminals of two wires concealed in the cord 7 and thepiston 19 and bushing 16 be considered as terminals of the wires 20 and21 these terminals might be variously connected up for switchingpurposes, as, for example, the terminals 10 and 11 might be connected orintegral and the wires in the cord 7 be dispensed with, then the switchwhen closed would connect the wires 20 and 21, while, on the contrary,the wires 20 and 21 1night be directly connected when the two wires incord 7 would, by means of their terminals 10 and 11, be connected bythat short circuit when the switch is closed, or the wires 20 and 21 mayform an outlying-loop to other subscribers to be connected by theterminals and cordwires. In service this switch-plug 5 is taken by theoperator and inserted in a socket 15, pushing the spring 18 down, asshown in Fig. 1V, and then the plug is twisted around, bringing the lugs12 and 13 into the sidewise offset recesses, as shown by dotted lines 22and 23, whereby the tendency of the spring to throw the plug out isresisted and contact between the metal lugs 12 13 and the metallicbushing 16 is insured. The spring 18 also insures con tact between itspiston 19 and the metallic section 11 of the plug. By this means veryeasy-working switch-plugs are insured perfect metallic contact withother members of the spring-jack, whereby much time and strength oftheoperator are saved and perfect connections are insured.

Having thus fully described my invention, within the socket, andelectric connections what I believe to be new, and desire to secure forthe socket and spring substantially as deby Letters Patent, is thefollowing: scribed.

The combinationin spring-jacks OfELSWitGh- In testimony whereof I affixmy signature 5 plug having one or more laterally-projecting in presenceof two Witnesses.

lugs connected With line-Wires a switchboard provided with a socket toreceive the said WILLIAM I plug freely, the said socket having longitu-\Vitnesses: dinal slots with sidewise recesses to receive JOHN Z.MILLER,

10 the said lugs; a longitudinally-acting spring LOUISE FRINK.

